Type-check notebooks in CI and fix typing/library usage issues

[darthtrevino]

Summary

Adds notebook type-checking to the CI pipeline and fixes the library-usage and typing issues it surfaced across the example notebooks.

A new check_notebooks poe task runs nbqa pyright over docs/notebooks/, and is wired into the top-level check sequence so notebook regressions are caught alongside the rest of the lint/type-check suite.

Changes

• pyproject.toml: add nbqa + pyright notebook check task and include it in the aggregate check task.
• docs/notebooks/*.ipynb: fix typing and API-usage issues flagged by pyright (imports, argument types, removed/renamed APIs, etc.).
• benchmark_qed/autoe/utils/stats.py: minor typing fix uncovered while validating notebook usage.
• uv.lock: refreshed for the added dev tooling.

Note on asyncio.run vs. top-level await

Several notebook cells previously used top-level await (which is valid in Jupyter). The verification path we adopted, nbqa pyright, concatenates all cells into a single synthetic .py module and runs the pyright CLI over it. In that flattened form, top-level await is reported as a hard parse error ("await" allowed only within async function), and pyright emits no rule name for this diagnostic — so it cannot be silenced via # pyright: ignore[<rule>] or [tool.pyright] settings. (Pyright's notebook-aware mode only exists in the language-server path used by Pylance, not the CLI; nbqa is the standard workaround for CLI-based notebook checking.)

To keep the CI check meaningful without resorting to bare # pyright: ignore comments scattered throughout, the affected calls have been rewritten to use asyncio.run(...). The notebooks still execute identically end-to-end; only the syntax around the async entry-points changed.

Validation

• uv run poe check (includes check_notebooks) passes locally.
• Notebooks were verified to still execute against the AP_news sample dataset.